CIRCUIT FOR DETECTING AC FOR POWER SUPPLY

摘要

PURPOSE: An alternating current detecting circuit for power supply is provided to reduce the manufacturing cost by remarkably reducing the number of components using shunt regulator and transistor. CONSTITUTION: A rectifier(100) rectifies the AC voltage. A voltage divider(200) partitions the voltage rectified by the rectifier into the predetermined voltage. A voltage stabilization circuit unit(300) stabilizes the voltage partitioned by the voltage divider. A shunt regulator(400) compares the input voltage stabilized by the voltage stabilization circuit unit and the internal voltage reference.